President Obama had a complex relationship with environmentalists during his first term. Many bemoaned that he didn't fight for a climate bill the way he fought for health-care reform, and others grumbled about his mixed signals on issues like Arctic oil drilling and the Keystone XL oil pipeline. Obama often responds by citing his efforts to improve U.S. fuel-efficiency standards, and while his updated mileage rules may not put a big dent in climate change, they're still kind of a big deal — as the Department of Energy argues in this new infographic:

DOE fuel efficiency infographic

Infographic courtesy of Sarah Gerrity/DOE

Related fuel-efficiency stories on MNN:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.

Fuel efficiency: The gift that keeps on giving [Infographic]
The U.S. Energy Department explains the economic and ecological perks of its new fuel-efficiency standards for cars and trucks.